<!DOCTYPE html>
<html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
       
    </head>
    <body>
        <p id="pid">

        </p>
        <script>
            function demo(a,b){
                if(a>b){
                    return "a比较大"
                }
                else{
                    return"b比较大"
                }
            }
            document.getElementById("pid").innerHTML=demo(10,9);
        </script>

    </body>
</html>